Closure device for a reclosable pouch

ABSTRACT

A reclosable pouch includes first and second pouch walls having male and female closure elements disposed on and separate from the first and second pouch walls, respectively. The female profile element includes a female profile member and first and second flanges integral with and disposed on either side of the female profile. Each of the first and second flanges includes a first portion of substantially uniform thickness and a second portion having a thickness less than the first portion and where the second portion is disposed between and contiguous with the first portion and the female profile member.

TECHNICAL FIELD

[0001] The present invention relates to closures for reclosable pouches,and more particularly, to such closures wherein at least one flange isdisposed on a surface of the bag adjacent a closure element.

BACKGROUND ART

[0002] A thermoplastic bag for the storage of items typically includes aclosure mechanism comprising male and female closure elements orprofiles attached to bag walls. In addition, thermoplastic bags areknown having guide ribs disposed on one or more internal surfaces of thethermoplastic bag closely spaced and adjacent the closure elements ofthe bag to assist in aligning the male and female closure elements whensealing the bag.

[0003] Hugues et al., U.S. Pat. No. 4,672,723 discloses a stabilizedreclosable extruded plastic fastener. The fastener comprises a femaleprofile on one wall of an extruded film material and a male profile onan opposite wall of the film material. Alignment ribs are spacedalongside and integral with a base area of the male profile tofacilitate alignment of the male profile with the female profile duringclosing of the fastener.

[0004] Fisher, U.S. Pat. No. 4,736,496, owned by the assignee of thepresent application, discloses a wide-track integral thermoplasticclosure for a reclosable thermoplastic container. The closure includesribs on either side of an element of the closure to assist in guiding auser's fingers during closure of the thermoplastic container.

[0005] Wirth et al., U.S. Pat. No. 5,198,055 discloses two profilestrips wherein each strip includes a reclosable element, preferably arib element and a groove element. Each of the profile strips furtherinclude a flange element spaced on one side of the profile strip and aheat barrier means associated with an inside face or front side of eachflange element, wherein the heat barrier section includes a thickenedportion of each flange element.

[0006] Tilman, U.S. Pat. No. 5,209,572 discloses a reclosable plasticbag having a sliderless zipper. The bag includes front and rear wallssealed along three edges to form a mouth or opening. Male and femaleprofiles are attached to internal surfaces of the front and rear walls,respectively, wherein the male and female profiles are engageable toclose the opening. Two ribs are provided on an outside surface of thefront wall, one on each side of the male profile, to define a valleytherebetween. Similarly, two additional ribs are formed on the outsidesurface of the rear wall, one on each side of female profile, to definea valley therebetween. The valleys act as finger guides for the user ofthe bag.

[0007] Scott et al., U.S. Pat. No. 5,368,394 discloses a stabilizerwedge zipper for reclosable bags. The zipper includes male and femaleprofiles wherein each of the profiles includes a stabilizer wedge onboth sides thereof. The stabilizer wedges are parallel to the profilesand span the width of the bag in order to maintain a wide-track feel asa user closes a bag.

[0008] Johnson, U.S. Pat. No. 5,577,305 discloses a fastener assemblyfor reclosable plastic containers. The assembly includes male and femalebase members each having male and female closure elements, respectively,and flanges attached thereto having ribs proximate the distal ends ofthe flanges. The ribs extending from the male base member are angledsubstantially perpendicular to the base and the ribs extending from thefemale base member are angled inwardly at approximately 70 degrees fromthe female base member. The position and orientation of the ribsincreases the holding power of the female closure element wheninterlocked with the male closure element.

SUMMARY OF THE INVENTION

[0009] According to one aspect of the present invention, a closure for apouch having first and second pouch walls includes male and femaleclosure elements disposed on and separate from the first and secondpouch walls, respectively. The female closure element includes a femaleprofile member and first and second flanges integral with and disposedon either side of the female profile member. Each of the first andsecond flanges includes a first portion of substantially uniformthickness less than half of a thickness of the female profile member anda second portion having a thickness less than the thickness of the firstportion and where the second portion is disposed between and contiguouswith the female profile member and the first portion.

[0010] According to another aspect of the present invention, areclosable plastic container includes first and second oppositelydisposed pouch walls and male and female closure elements disposed onand separate from the first and second pouch walls, respectively. Thefemale closure element includes a female profile member and first andsecond flanges integral with and disposed on either side of the femaleprofile member. Each of the first and second flanges includes a firstportion of substantially uniform thickness less than half of a thicknessof the female profile member and a second portion having a thicknessless than the thickness of the first portion where the second portion isdisposed between and contiguous with the female profile member and thefirst portion.

[0011] According to yet another aspect of the present invention, azipper tape includes male and female closure elements disposed on firstand second surfaces, respectively. The female closure element includes afemale profile member and first and second flanges integral with anddisposed on either side of the female profile member. Each of the firstand second flanges includes a first portion of substantially uniformthickness less than half of a thickness of the female profile member anda second portion having a thickness less than the thickness of the firstportion and where the second portion is disposed between and contiguouswith the female profile member and the first portion.

[0012] According to another aspect of the present invention, a closurefor a pouch includes male and female closure elements disposed on firstand second pouch walls, respectively. The female closure elementincludes a female profile member and first and second flanges integralwith and disposed on either side of the female profile member. Each ofthe first and second flanges has a substantially uniform thickness lessthan half of a thickness of the female profile member.

[0013] According to yet another aspect of the present invention, aprofile plate includes a substantially planar base portion and twoprofile portions symmetrical about a center of the base portion andextending from a first surface of the base portion. The base portionextends a distance beyond the profile portions equal to or greater thana thickness of the profile portions.

[0014] Other aspects and advantages of the present invention will becomeapparent upon consideration of the following detailed description andthe attached drawings, in which like elements are assigned likereference numerals.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is an elevational view of a reclosable thermoplasticstorage bag according to the present invention;

[0016]FIG. 2 is an enlarged, fragmentary, sectional view taken generallyalong the lines 2-2 of FIG. 1;

[0017]FIG. 3 is an enlarged sectional view similar to FIG. 2illustrating bags produced in accordance with the present invention;

[0018]FIGS. 4 and 5 are enlarged, fragmentary, sectional view similar toFIG. 2 illustrating further embodiments of the present invention;

[0019]FIG. 6 is an enlarged, fragmentary, elevational view of a portionof zipper tape according to the present invention;

[0020]FIG. 7 is an isometric view of an apparatus for producing bags ofthe present invention;

[0021]FIG. 8 is an enlarged isometric view of the apparatus of FIG. 7;

[0022]FIG. 9 is an enlarged end elevational view of the apparatus ofFIGS. 7 and 8; and

[0023] FIGS. 10-13 are bottom elevational views of extrusion die profileplates that may be used to produce female closure elements forthermoplastic storage bags of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Referring to FIG. 1, a reclosable pouch in the form of athermoplastic storage bag 20 comprises first and second body portions22, 24 joined to one another to form first and second bag walls 26, 28.The first and second bag walls 26, 28 are joined at first and secondside portions 30, 32, respectively, and at a bottom portion 34. Anopening 35 is disposed at a top portion 36 of the bag 20. A closuremechanism 38 and two lips 40 are also disposed at the top portion 36 ofthe bag 20.

[0025] Referring to FIGS. 2 and 3, female and male closure elements 42,44 of the closure mechanism 38 are disposed on opposing inside surfaces46, 48 of the first and second body portions 22, 24, respectively. Thefemale element 42 comprises a base 62 with a C-shaped profile member 64extending therefrom, wherein the female element 42 is adapted to receivethe male element 44 when pressure is exerted on the closure elements bya user's finger(s) during closing of the bag. According to a firstembodiment, the female closure element 42 further comprises flanges 70attached to each side of the base 62 of the female closure element 42and extending outwardly towards the bottom 34 and top 36 portions of thebag along the inside surface 46.

[0026] The male closure element 44 comprises a base 58 integral withflanking side members 54 and 56 and an arrow-shaped profile member 60that extends from the base 58. The side members 54 and 56 are of asufficient size and proximity to the profile member 60 such that theside members 54 and 56 move together with the member 60 when the members60 and 64 are engaged and disengaged. The side members 54 and 56 alsohave a height less than the height of the profile member 60, and themembers 54 and 56 extend beyond tips 68 of the C-shaped profile member64 when the profile member 60 is engaged with the C-shaped profilemember 64. Thus, at such time, the tips 68 of the C-shaped profilemember 64 reside between the side members 54 and 56 and the male profilemember 60.

[0027] The flanges 70 associated with the female closure element 42include a first portion 72 and a second portion 74 having a thicknessless than a thickness of the first portion 72. The second portion 74 isdisposed adjacent the C-shaped profile member 64 and connects the firstportion 72 to the C-shaped profile member 64. The second portion 74 hasa thickness of between about 0.001 inch and about 0.005 inch andpreferably about 0.0018 inch. The first portion 72 has a thickness ofbetween about 0.03 inch and about 0.06 inch and preferably about 0.047inch, wherein the first portion 72 has either a generally uniformthickness throughout a length thereof as seen in FIG. 2 or a varyingthickness throughout a length thereof by adding ribs 77 to a surface 79thereof as seen in FIG. 3. The second portion 74, therefore, has athickness about one-quarter the thickness of the first portion 72 and isnot completely attached to the inside surface 46 adjacent the C-shapedprofile member 64, thereby creating a gap 76 between the second portion74 of the flanges 70 and the inside surface 46. The C-shaped profilemember 64 has a thickness between about 0.035 inch and 0.06 inch,preferably about 0.043 inch. The flanges 70 are colored the same coloras the C-shaped profile member 64 and the base 62, thereby providing alarger colored area to the closure mechanism 38 and providing a widerarea for tactile feedback.

[0028] If desired, one or more gripping ribs 75 may be disposed on theinside surfaces 46, 48 of the bag 20 between the closure elements 42 and44 and the top portion 36 of the bag 20 as seen in FIG. 2, wherein thegripping ribs 75 are integrally extruded with the walls of the bag. Anynumber of gripping ribs 75 can be used, although space is necessarybetween adjacent ribs in order to facilitate a gripping action with auser's fingers. In a preferred embodiment, about six or seven grippingribs 75 are disposed on each lip 40 of the bag.

[0029] In other embodiments, as seen in FIGS. 4 and 5, the femaleclosure element 42 and the male closure element 44 may both have flanges70 each having a first portion 72 and a second portion 74. Some or allof the second portions 74 may have a thickness less than that of thefirst portions 72 as seen in FIG. 4. Alternatively, some or all of thesecond portions 74 may have a thickness equal to that of the firstportions 72 as seen in FIG. 5.

[0030] Another embodiment as shown in FIG. 6 comprises a zipper tape 78.The zipper tape 78 includes first and second thermoplastic strips 80,82, wherein female and male closure elements 42, 44 are attached to orotherwise formed on the first and second thermoplastic strips 80, 82,respectively. The female closure element 42 further comprises flanges 70attached to each side of the base 62 of the female closure element 42and extending outwardly towards an upper portion 84 of the first strip80 and a lower portion 86 of the first strip 80. The zipper tape 78 maybe attached to a folded thermoplastic sheet by any suitable conventionalprocess and apparatus and the resulting structure may be severed andsealed at spaced locations to form individual bags.

[0031] Reclosable thermoplastic storage bags as described herein can beproduced by any conventional bag-making process, such as a cast postapplied process, a cast integral process, a blown process, or any otherprocess known in the art. An alternative post applied process can alsobe used such as seen in FIGS. 7 and 8. Referring to such FIGS., thealternative post applied process utilizes an extrusion apparatusincluding a first extrusion slot die 88, a temperature-controlled drivencasting roll 90, edge pinning devices or apparatus 92 a, 92 b, an airknife 94, second and third extrusion dies 96 a, 96 b (which, togetherwith the die 88, form the extrusion apparatus) and cooling apparatus 98a, 98 b. The extrusion die 88 receives molten thermoplastic from anextruder (not shown) and deposits the thermoplastic in sheet form as aweb 100 onto the casting roll 90. The extrusion die 88 includes a slotopening (not shown) that forms thickened areas 102, 104 at outside edgeportions 106 a, 106 b of the resulting web 100 and a relatively thinnerportion 108 intermediate the thickened areas 102, 104. The edge portions106 a, 106 b are pinned to the casting roll 90 by the edge pinningdevices 92 a 92 b, respectively. The web 100 is then pinned across theentire width thereof (i.e., as a whole) to the casting roll 90 by theair knife 94.

[0032] After the web 100 is pinned to the casting roll 90, the male andfemale closure elements 42, 44 are formed on the web 100. Preferably,the extrusion dies 96 a, 96 b receive molten thermoplastic from separateextruders and extrude the male and female closure elements 42, 44,respectively, onto the thickened areas 102, 104. Alternatively, theseparate extrusion dies 96 a, 96 b may be replaced by a single extrusiondie having two outlets at which the male and female closure elements 42,44 are simultaneously extruded onto the thickened areas 102, 104. In anyevent, as seen in FIG. 7, the angle of a face 110 of each die 96 is atleast initially disposed substantially parallel to a horizontal (as seenin FIG. 9) radial line 111 extending from the center of the casting roll90. The position of the die 96 (or each die 96 a, 96 b individually ifseparate dies are used) may then be adjusted by moving the die left,right, up, or down (all as seen in FIG. 9) or the die may be tipped(i.e., angularly displaced) to adjust the angle of the die face 110 toobtain desirable results. The closure elements 42, 44 formed by thedie(s) 96 may exit the die(s) 96 at a point coincident with a verticaltangent line 112 (FIG. 9) intersecting the surface of the casting roll90 on the side of the casting roll 90 where the web 100 is firstdeposited thereon. Alternatively, the closure elements 42, 44 formed bythe die(s) 96 may exit the die(s) 96 at a point displaced to the rightor left (as seen in FIG. 9) of the tangent line 112. If the extrudateexits the die(s) 96 at a point displaced to the right of the line 112,some provision must be made at the initiation of production to attachthe extrudate stream to the casting roll 90. Thereafter, production maycommence, (provided that the exit of the die(s) 96 is not disposed toofar to the right of the tangent line 112) whereupon the melt strength ofthe extrude stream carries the stream into contact with the roll 90.

[0033] Once the molten thermoplastic from the die(s) 96 has beendeposited onto the web 100, coolant is applied to the closure elements42, 44 by the coolant apparatus 98 a, 98 b to bring the temperaturethereof below the melting point of the thermoplastic material formingthe closure elements 42, 44 as quickly as possible. Preferably, thecoolant comprises water or any other suitable cooling fluid and thecoolant is applied to the material of the closure elements 42, 44 onlyafter such material contacts the material of the web 100 so thatadhesion thereto is optimized. The web 100 and the closure elements 42,44 are maintained in contact with the temperature-controlled castingroll 90 for a period of time as the roll 90 is rotated so that the web100 and closure elements 42, 44 are further cooled. The casting roll 90should be maintained at a temperature below the melting point of thethermoplastic material(s) forming the web 100 and the closure elements42, 44, typically about 20-80 degrees C.

[0034] Profile plates as seen in FIGS. 10-13 may be utilized in anysuitable process to produce thermoplastic bags having a female closureelement 42 with flanges 70 according to the present invention. Theprofile plate 130 includes a base portion aperture 132 to create thebase 62 of the female closure element 42 and the flanges 70, wherein thebase portion aperture 132 can have horizontal end portions 134 as inFIGS. 10-13 or upwardly curving end portions 134 as in FIG. 13. Twoprofile portions apertures 136 are disposed symmetrically about a center138 of the base portion aperture 132 of the profile plate 130, whereineach of the profile portions apertures 136 include a tip portion 139 anda leg portion 142. The leg portion 142 of each of the profile portionapertures 136 may be disposed perpendicular to the base portion aperture132 as seen in FIG. 11, or may be at a slight angle outwardly withrespect to a vertical axis as seen in FIGS. 10, 12, and 13. The legportion 142 of each profile portion aperture 136 may also be slightlycurved or arched (not seen). Notches 140 may be created in the baseportion aperture 132 adjacent the profile portion apertures 136 tocreate the second, thinner portions 72, wherein a thickness of thenotches 140 is about half a thickness of the base portion aperture 132and the end portions 134. The notches 140 reduce the interaction betweenthe base 62 and the flanges 70 during deposition of molten thermoplasticto form the female closure element 42. This reduction in interactionallows formation of the C-shaped profile member 64 in a substantiallyundeformed shape as compared with the shape produced when the flanges 70are not present. That is, if the notches 140 were not included in theprofile plate 130 as seen in FIG. 10, the flanges 70 would be formedproperly, but the C-shaped profile member 64 would tend to spread apart(i.e. would be formed with a greater distance between the tips 68 of theC-shaped profile member 64), thereby possibly adversely affecting theengagement of the C-shaped profile member 64 with the arrow-shapedprofile member 62. Proper formation of the female closure element 42 canbe attained using no notches 140 as seen in FIG. 10, but the variabilitywould be greater.

Industrial Applicability

[0035] Closure devices according to the present invention areparticularly useful for resealable closures for thermoplastic bags orpouches. Such closure devices include a male and a female profileswherein the female profile includes flange portions extending along aninside surface of a bag or pouch wall. The flange portions of the femaleprofile provide a wider surface for increased tactile confirmation thatclosure has been achieved.

[0036] Numerous modifications will be apparent to those skilled in theart in view of the foregoing description. Accordingly, this descriptionis to be construed as illustrative only and is presented for the purposeof enabling those skilled in the art to make and use the invention andto teach the best mode of carrying out same. The exclusive rights to allmodifications which come within the scope of the appended claims arereserved.

I claim:
 1. A closure for a pouch having first and second pouch walls,comprising: male and female closure elements disposed on and separatefrom the first and second pouch walls, respectively; wherein the femaleclosure element includes a female profile member and first and secondflanges integral with and disposed on either side of the female profilemember; wherein each of the first and second flanges includes a firstportion of substantially uniform thickness less than half of a thicknessof the female profile member and a second portion having a thicknessless than the thickness of the first portion and where the secondportion is disposed between and contiguous with the female profilemember and the first portion.
 2. The closure of claim 1, wherein themale closure element is colored a first color and the female closureelement is colored a second color.
 3. The closure of claim 1, whereinthe thickness of the second portion of each flange is between about0.001 inch and about 0.005 inch.
 4. The closure of claim 3, wherein thethickness of the second portion of each flange is about 0.0018 inch. 5.The closure of claim 1, wherein the thickness of the first portion ofeach flange is between about 0.03 inch and about 0.06 inch.
 6. Theclosure of claim 5, wherein the thickness of the first portion of eachflange is about 0.047 inch.
 7. The closure of claim 1, wherein at leastone of the flanges includes ribs on a surface of the flange(s).
 8. Theclosure of claim 1, wherein the male closure element includes a maleprofile member and first and second flanges integral with and disposedon either side of the male profile member.
 9. The closure of claim 8,wherein each of the first and second flanges integral with the maleprofile member includes a first portion of substantially uniformthickness less than half of a thickness of the male profile member and asecond portion having a thickness less than the thickness of the firstportion and where the second portion is disposed between and contiguouswith the male profile member and the first portion.
 10. A reclosableplastic container, comprising: first and second oppositely disposedpouch walls; male and female closure elements disposed on and separatefrom the first and second pouch walls, respectively; wherein the femaleclosure element includes a female profile member and first and secondflanges integral with and disposed on either side of the female profilemember; wherein each of the first and second flanges includes a firstportion of substantially uniform thickness less than half of a thicknessof the female profile member and a second portion having a thicknessless than the thickness of the first portion and where the secondportion is disposed between and contiguous with the female profilemember and the first portion.
 11. The container of claim 10, wherein themale closure element is colored a first color and the female closureelement is colored a second color.
 12. The container of claim 10,wherein the thickness of the second portion of each flange is betweenabout 0.001 inch and about 0.005 inch.
 13. The container of claim 12,wherein the thickness of the second portion of each flange is about0.0018 inch.
 14. The container of claim 10, wherein the thickness of thefirst portion of each flange is between about 0.03 inch and about 0.06inch.
 15. The container of claim 14, wherein the thickness of the firstportion of each flange is about 0.047 inch.
 16. The container of claim10, wherein at least one of the flanges includes ribs on a surface ofthe flange(s).
 17. The container of claim 10, wherein the male closureelement includes a male profile member and first and second flangesintegral with and disposed on either side of the male profile member.18. The closure of claim 17, wherein each of the first and secondflanges integral with the male profile member includes a first portionof substantially uniform thickness less than half of a thickness of themale profile member and a second portion having a thickness less thanthe thickness of the first portion and where the second portion isdisposed between and contiguous with the male profile member and thefirst portion.
 19. A zipper tape, comprising: male and female closureelements disposed on first and second surfaces, respectively; whereinthe female closure element includes a female profile member and firstand second flanges integral with and disposed on either side of thefemale profile member; wherein each of the first and second flangesincludes a first portion of substantially uniform thickness less thanhalf of a thickness of the female profile member and a second portionhaving a thickness less than the thickness of the first portion andwhere the second portion is disposed between and contiguous with thefemale profile member and the first portion.
 20. The zipper tape ofclaim 19, wherein the male closure element is colored a first color andthe female closure element is colored a second color.
 21. The zippertape of claim 19, wherein the thickness of the second portion of eachflange is between about 0.001 inch and about 0.005 inch.
 22. The zippertape of claim 21, wherein the thickness of the second portion of eachflange is about 0.0018 inch.
 23. The zipper tape of claim 19, whereinthe thickness of the first portion of each flange is between about 0.03inch and about 0.06 inch.
 24. The zipper tape of claim 23, wherein thethickness of the first portion of each flange is about 0.047 inch. 25.The zipper tape of claim 19, wherein at least one of the flangesincludes ribs on a surface of the flange(s).
 26. The zipper tape ofclaim 19, wherein the male closure element includes a male profilemember and first and second flanges integral with and disposed on eitherside of the male profile member.
 27. The zipper tape of claim 26,wherein each of the first and second flanges integral with the maleprofile member includes a first portion of substantially uniformthickness less than half of a thickness of the male profile member and asecond portion having a thickness less than the thickness of the firstportion and where the second portion is disposed between and contiguouswith the male profile member and the first portion.
 28. A closure for apouch having first and second pouch walls, comprising: male and femaleclosure elements disposed on and separate from the first and secondpouch walls, respectively; wherein the female closure element includes afemale profile member and first and second flanges integral with anddisposed on either side of the female profile member; and wherein eachof the first and second flanges have a substantially uniform thicknessless than half of a thickness of the female profile member.
 29. Theclosure of claim 28, wherein the male closure element is colored a firstcolor and the female closure element is colored a second color.
 30. Theclosure of claim 28, wherein the thickness of each flange is betweenabout 0.03 inch and about 0.06 inch.
 31. The closure of claim 30,wherein the thickness of each flange is about 0.047 inch.
 32. Theclosure of claim 28, wherein at least one of the flanges includes ribson a surface of the flange(s).
 33. The closure of claim 28, wherein themale closure element includes a male profile member and first and secondflanges integral with and disposed on either side of the male profilemember.
 34. The closure of claim 28, wherein each of the first andsecond flanges integral with the male profile member has a substantiallyuniform thickness less than half of a thickness of the male profilemember.
 35. A profile plate, comprising: a substantially planar baseportion; two profile portions symmetrical about a center of the baseportion and extending from a first surface of the base portion; andwherein the base portion extends a distance beyond the profile portionsequal to or greater than a thickness of the profile portions.
 36. Theprofile plate of claim 35, wherein notches are formed in the firstsurface of the base portion.
 37. The profile plate of claim 36, whereinthe notches are formed adjacent to each of the profile portions.
 38. Theprofile plate of claim 36, wherein the notches have a thickness that isabout half the thickness of a thickness of the base portion.
 39. Theprofile plate of claim 35, wherein the profile portions extendperpendicularly from the first surface of the base portion.
 40. Theprofile portion of claim 35, wherein the profile portions extend from afirst surface of the base portion at a slight angle outwardly of avertical axis through the center of the base portion.